최근 에너지절약 및 자원절약 차원으로 전 세계적으로 가전제품 및 자동차 부품 등에 대하여 재사용, 재활용, 재제조 등에 대한 법적 규제 및 의무화를 추진하고 있으나 아직 우리나라는 재제조에 대한 판심과 정부의 지원 정책이 이루어지고 있으나 아직 활발하게 산업 발전이 이루어지지 못하고 있는 실정 이다. 득히 자원순환법이 고시되면서부터 재제조에 대한 인식과 이에 판련된 부품의 재제조 기초연구를 버롯한 기반기술 개발이 진행되고 있으며 디양한 부품에 대하여 재제조 기술 개발 및 품질인증이 추진되고 있다. 따라서, 본 논문에서는 자동차 부품의 승차감올 향상시키는 쇽업쇼버에 대하여 재제조와 관련된 재제조 공정을 비롯하여 재제조 검사기준 등에 대하여 연구하여 관련 산업체에서 활용 가능하게 연구하였다.
This study was undertaken to find out the effect of methyl-beta-cyclodextrin (MBCD) on cold shock and membrane cholesterol quantity of sperm during the freezing process in miniature pigs. For this study, semen ejaculated from PWG M-type miniature pig was diluted that freezing solution (with egg yolk group) and m-Modena B (without egg yolk group) treated with 0, 1, 5, 10 and 20 mM MBCD before freezing process. The diluted semen was monitored sperm ability at room temperature, after cooled until 5℃ and after forzen-thawed for cold shock test of spermatozoa. Also, membrane cholesterol of sperm was extracted by folch solution at the same time. sperm ability was assessed for viability and acrosomal status. The membrane cholesterol quantity was measured by thin-layer chromatography (TLC) method. The result, viability and acrosome integrity in semen diluted without egg yolk groups were decreased at all temperature range by increasing of MBCD concentration. In particular, sperm of egg yolk group was showed that significantly higher viability and lower acrosome damage when treated with 5 mM MBCD (p<0.05). The results of TLC experiment, cholesterol amounts were increased with MBCD cocentration in egg yolk, and decreased with MBCD concentration in m-Modena B. In cryopreservation efficiency, there was no significant difference at viability, and acrosomal state of sperm in 5 mM MBCD concentration was significantly lower in acrosome damage than other groups (p<0.05). Therefore, the addition MBCD in egg yolk was protected spermatozoa from cold shock injury. This protective effect of MBCD may be due to addition of sperm membrane cholesterol.
쇽옵서버 피스톤로드(shock absorber piston rod)는 자동차의 충격과 진동의 흡수에 작용하는 자동차 현가장치(sus-pension equipment)부품의 일종이다. 피스톤로드는 자동차 충격흡수에 매우 밀접한 영향을 주기 때문에 제조에 있어서 고도의 정밀도와 표면 매끄러움이 요구된다. 피스톤로드의 제조공정은 선삭, 홈가공, 밀링, 건조 등 여러 공정으로 구성되는데, 여기서 품질불량에 가장 크게 영향을 주는 공정은 선삭공정(lathing
The objective of this study was to examine and compare to transient response to quantitative and hydraulic shocks which produce equal changes in mass rate of organic feed in aerobic fixed-film process. The general experimental approach was to operate the system at several growth rates under steady-state(pre-shock) conditions, then to apply step changes during day 3 in dilution rate(hydraulic shock), or feed concentration(quantitative shock) at the same organic mass loading rate. Performance was assessed in both the transient state and the new steady-state (post-shock). Shock load of different type did not produced equivalent disruptions of effluent quality for equal increases on mass loading rate. Based on effluent concentrations, a hydraulic and a quantitative shock at the same mass loading caused equal increase in total effluent COD, but the increase was primarily a result of suspended solids the hydraulic shock and COD in the quantitative shock, The time which effluent COD came to peak values were about 32∼48 hours at the low organic loads and 52∼72 hours at the high organic loads, respectively. A quantitative shock produced a much greater increase in effluent COD than did a hydraulic shock at the same mass loading. Mean and peak values of effluent concentration were increased in 2.8∼4.2 times at low organic loading rate, 5.2∼6.6 times at the high organic loading rate respectively.